Both resting and preactivated T lymphocytes are susceptible for AICD.

Strongly decreased proliferation of responders after induction of AICD independent of whether alloreactive T cells had been subjected to anti-CD95 treatment during primary or secondary stimulation. Small resting CD4⁺ T cells (H-2^k) or CD4⁺T cells preactivated by TCR cross-linking using anti-CD3 mAb (145-2C11) for 3 days were stimulated with irradiated allogeneic splenic stimulators (H-2^d) in bulk culture in the presence of agonistic anti-CD95 mAb for 5 days. Residual T cells collected from these cultures were then tested for alloreactivity to the H-2^d alloantigen in a 5-day MLC. Results are expressed as mean ± SD of triplicate wells and show 1 of at least 3 representative experiments. (A) Alloreactivity of responders primarily stimulated to H-2^d alone (▪) or in the presence of anti-CD95 mAb (●). (B) Alloreactivity of anti-CD3–preactivated responders after restimulation to H-2^d alone (▪) or in the presence of 1 μg/mL anti-CD95 mAb (●). Syngeneic controls are shown without (■) or with (○) induction of AICD.